Senate GOP leaders plan to unveil a revised health-care proposal Thursday that would allow insurers to sell austere plans that do not comply with requirements imposed under the Affordable Care Act, according to three Republicans familiar with the plans.

The Republicans, who spoke on condition of anonymity because they were not authorized to speak on the record, said the proposal would incorporate a version of a controversial proposal from Sen. Ted Cruz (R-Texas), which conservatives have been pushing vocally during the last few weeks in an effort, they say, to lower premiums and give consumers more choices.

Details of the proposal were closely guarded Thursday morning, and it was unclear what precise form the Cruz idea would take in the final bill.

Cruz’s plan would allow insurers to sell plans that don’t comply with Obamacare coverage requirements, such as mandated coverage of preventive care and mental and substance abuse treatment, provided they offer at least one that does.

Critics, including insurers, believe that providing the option of skimpier plans would draw younger, healthier consumers into a separate risk pool. That development would drive up rates for the Americans buying more comprehensive coverage on the individual market, which could in turn destabilize the entire market. It remains unclear how the new McConnell bill would address concerns about the risk pools.

Senate leaders are leaving themselves the option of jettisoning the Cruz proposal, however, after they get a Congressional Budget Office analysis early next week that will gauge its impact on both the budget and the overall number of uninsured.

Majority Leader Mitch McConnell (R-Ky.) is expected to brief Republican senators on the revamped bill to roll back key parts of the Affordable Care Act at 11:30 a.m., according to Republican senators and aides.

A GOP senator and other Republicans familiar with the effort said they expect the new bill to offer more generous insurance subsidies than the first version. Republicans also said McConnell is willing to preserve a pair of taxes on wealthy Americans that would have been repealed under the original bill.

Senate Majority Whip John Cornyn (R-Texas) said Thursday that he expects the CBO will release two scores for the bill but would not confirm what those scores would include or when when will be released.

“We are expecting a CBO score but I can’t tell you exactly what the format will be,” Cornyn told reporters. “The Lee and Cruz amendment will be scored.”

The Cruz amendment underwent several iterations in recent weeks and the proposal is still being considered by analysts at the CBO, according to two GOP aides familiar with the process. As a result, the CBO is expected to release one score without the Cruz provisions and another that will provide further details on the Cruz amendment.

The changes remain controversial among moderates who worry the Cruz proposal could drive up premiums for sicker, older Americans and Cornyn stopped short of promising the changes would be enough to ensure the bill will pass.

“We will have the votes when we start voting,” Cornyn said.

The release will come a day after President Trump intensified public pressure on McConnell to shepherd the bill to passage, even as it remains unclear that he will have the votes to do that next week, when he intends to bring it to the Senate floor.

“I am sitting in the Oval Office with a pen in hand, waiting for our senators to give it to me,” Trump said in an interview with televangelist Pat Robertson of CBN News. “It has to get passed. They have to do it. They have to get together and get it done.”

Conservative lawmakers and activists have voiced concerns that McConnell’s revamped measure will not undo the ACA, known as Obamacare, aggressively enough. Those worries, alongside lingering anxiety among centrist Republicans that the bill is going too far, has put McConnell at serious risk of losing more GOP votes than he can afford. If more than two GOP senators defect, the bill cannot pass.

Cruz has argued that his idea would provide consumers with more choice. But critics assert that it would lead to less healthy people ultimately paying more for coverage.

Sen. Bob Corker (R-Tenn.) said he believes McConnell will release two versions of the revised bill on Thursday — one with Cruz’s amendment and one without it. GOP leaders were more circumspect.

“It needs to be in the underlying text,” Cruz told reporters Wednesday, dismissing the suggestion that he could instead introduce it during an open amendment process if and when the bill heads to the Senate floor.

McConnell hopes to have a score on his revised bill from the nonpartisan Congressional Budget Office by the beginning of next week. The CBO will forecast what the bill will do to insurance coverage levels nationwide over the next decade. It will also predict the measure’s impact on the federal budget deficit.